Well the Speed mod has 3 settings as far as i know, 600, 1200 and 3000(not sure 'bout this one)
But you have option to Double the thruster speed so ship goes at 400kph with thrusters, so here is the problem.
Maybe Igiss could ask makers of The Void mod, since when u activate it none of other mods can
be activated, not even the speed mod, and make the same for 4.85...
Maybe even reissue present mod...